Many dispensers are known in the prior art for serially dispensing folded sheet products such as paper napkins from a stack. Such dispenser apparatus range from the highly complex, incorporating relatively complicated and intricate mechanisms to effect dispensing, to the very simple, which may be little more than a box with a hole to permit manual access to the folded sheet product and removal thereof.
Many dispensers have been specifically designed for use in institutional environments. For example, fast-food restaurants make widespread use of paper napkin dispensers which characteristically include a housing for storing a stack of napkins and a nose piece or outlet element defining an opening through which the napkins are individually retrieved by a customer. Not uncommonly, great volumes of paper napkins are dispensed by such apparatus and they must be refilled relatively frequently by the restaurant staff.
Over-stuffing of the dispenser often occurs during the refilling operation. That is, persons replenishing the supply of paper napkins in the dispenser often refill it with more napkins than it is designed to accommodate.
Over-stuffing of a paper napkin dispenser can cause significant problems. Obviously, an over-filled dispenser will result in increased frictional forces not only between the napkins in the stack but between the end-most napkin and the end piece or dispensing element defining the opening through which the napkins are removed. It is occasionally virtually impossible to remove the end-most napkin without ripping or tearing it. The frustrated customer then, more often than not, resorts to manually extracting not just a single napkin but a whole pad consisting of several napkins. Even if such were not the case, significant waste of paper napkins occurs simply due to the ripping and tearing which occurs until enough paper napkins have been removed to sufficiently relieve stack pressure at the outlet.
A number of approaches have been devised to solve the over-fill problem. For example, it is known to provide a dispenser cabinet or housing with a refill opening which extends only part way along the housing, the idea being to allow some extra housing capacity. This approach, however, is not always successful because the person filling the cabinet or housing still may easily stuff more napkins into the housing than its capacity dictates. In other words, there is no positive means for preventing over-stuffing in such arrangements.
While mechanisms do exist which in effect expand the capacity of the housing after it has been filled to relieve stack pressure, such arrangements are characterized by their relative complexity and high cost. Furthermore, the reliability of some of these prior art systems is questionable.